Pump



Nov. 26, 1968 LA VERN CONNELLY 3,412,685

PUMP

Filed Sept. 16, 1966 2 Sheets-Sheet 1 INVENTOR LAVERN R. GOA/NELLY A T T'ORNE Y5 Nov. 26, 1968 LA VERN R CONNELLY 3,412,685

PUMP

2 Sheets-Sheet 2 Filed Sept. 16, 1966 FIG5 FICA

FIG?

INVENTOR LAVEEN R. CON/VELLY WWI/11V B Y ATTORNE vs United States Patent 3,412,685 PUMP La Vern R. Connelly, Marshall, Mich., assignor to Eaton Yale & Towne Inc., Cleveland, Ohio, a corporation of Ohio Filed Sept. 16, 1966, Ser. No. 580,090 7 Claims. (Cl. 103-136) ABSTRACT OF THE DISCLOSURE The present invention relates to a pump, and more particularly relates to a pump having improved means for communicating inlet fluid from an inlet chamber of the pump to inlet ports thereof to reduce pump noise and increase volumetric efficiency of the pump.

A pump embodying the present invention may include a housing containing a pumping means which is effective to pump fluid from the pump inlet to an outlet in response to rotation of a drive shaft which is connected therewith. The pumping means includes a rotor or carrier member, a stationary cam member, and a plurality of pumping elements cooperating with the cam and rotor to form pumping pockets and which are movable with the rotor on rotation of the drive shaft and are moved radially by the cam to vary the volume of the pumping pockets and effect pumping of the fluid.

An object of the present invention is the provision of a new and improved pump of the character referred to and wherein means are provided for controlling fluid pressures acting on the pumping elements during an inlet stroke thereof to maximize the volumetric efliciency of the pump, reduce wear of the parts thereof and minimize noise produced by the pump.

Another object of the present invention is the provision of a new and improved fluid pump for supplying fluid to an external fluid system comprising shaft means, rotary pumping means driven by the shaft means and having a rotor member which carries pumping rollers and a cam engaged by the rollers to move the rollers radially relative to the rotor to effect pumping of the fluid, a first member at one axial side of the pumping means including inlet passageways for the pump and inlet ports communicating the pumping means with the inlet passageways, a second member at the other axial side of the pumping means including inlet ports for the pumping means, and conduit means including a flow passage in the shaft for communicating the inlet passageways in the first member with the inlet ports in the second member whereby fluid enters the pumping means at opposite axial sides thereof.

Another object of the present invention is the provision of a new and improved pump as set forth in the next preceding paragraph wherein rotation of the shaft produces a centrifugal flow of fluid from the passageway in the shaft through a passage in the second member and to an inlet of the pumping means radially inwardly of the pumping rollers to provide pressure forces urging the rollers radially against the cam during an inlet stroke thereof to maximize the volumetric efficiency of the pump.

Yet another object of the present invention is the pro vision of a new and improved fluid pump-for supplying fluid to an external fluid system comprising a rotary pumping means which includes a rotor rotatable about an axis carrying a plurality of pumping roller elements and a surface operable to move the pumping elements radially relative to the rotor to provide for inlet and discharge pumping strokes of the pumping elements and in which conduit means are provided for equalizing radially inwardly directed pressure forces acting axially along the pumping elements during inlet strokes thereof to eliminate tilting and hopping of the pumping elements on the cam during the inlet stroke and thereby increasing the volumetric efliciency of the pump and reducing noise and wear of parts thereof.

Another object of the present invention is the provision of a new and improved fluid pump as set forth in the next preceding paragraph and wherein the conduit means includes a flow passageway in the cam member and extending between opposite axial sides of the pumping means at the inlet thereof and communicating with a radially outer portion of the pumping rollers.

A still further object of the present invention is the provision of a new and improved pump for supplying fluid to an external fluid system comprising rotary pumping means which includes a rotor, a cam member surrounding the rotor and a plurality of roller members carried by the rotor and movable radially with respect thereto by the cam to effect inlet and discharge pumping strokes, and a member adjacent a side of the pumping means having radially inner and outer inlet ports communicating with the pumping means and wherein the radially inner and outer inlet ports are interconnected by a fluid passageway which is effective to reduce differentials in fluid pres sure forces acting axially along the roller members during an inlet pumping stroke so that tilting and hopping of the rollers is minimized and a relatively high volumetric efficiency for the pump is obtained.

Other objects and advantages of the present invention will become apparent from the following detailed description thereof made with reference to the accompanying drawings and wherein:

FIG. 1 is a sectional view, partially in elevation, of a pump embodying the present invention;

FIG. 2 is a sectional view of the pump of FIG. 1, taken approximately along section line 22 thereof;

FIG. 3 is an enlarged fragmentary sectional view of a portion of the pump shown in FIG. 1;

FIG. 4 is a sectional view, taken approximately at line 44 of FIG. 1;

FIG. 5 is a sectional view, taken approximately at line 5-5 of FIG. 1;

FIG. 6 is an enlarged fragmentary sectional view of a portion of the pump of FIG. 2; and

FIG. 7 is a fragmentary view taken approximately along line 77 of FIG. 6.

A pump 10 embodying the present invention is shown in FIG. 1. While the pump 10 is preferably utilized in conjunction with a hydraulic power steering system in an automotive vehicle and driven from an engine of the vehicle, it will become apparent from the following description that a pump embodying the present'invention may be utilized in many different applications.

The pump 10 includes a housing 11 supporting a pumping means 12 therein. The pumping means 12 is a rotary pumping means secured to a driving shaft 13 for rotation therewith. The pumping means 12 includes a rotatable rotor member 14 secured to the shaft 13 and a stationary cam member 15 which is secured to the housing 11. The rotor member 14 is an annular member having a plurality of radial slots therein which carry pumping elements 16. As the rotor member 14 rotates, the pumping elements 16 engage a surface 20 of the cam member 15 to form pump ing pockets 21 and are moved radially inwardly and outwardly relative to the rotor member 14 by the cam surface to effect pumping of the fluid in a well known manner. The cam surface of the cam member 15 may be configured so as to provide any number of pumping strokes of the pumping elements 16 during a revolution of the rotor member 14 and has been illustrated as providing two such pumping strokes.

The pumping means 12 is supported in the housing 11 closely adjacent a planar surface 24 of a cover member 25. The cover member 25 includes inlet passageways 26, 26a therein which extend between the pumping means 12 and a fluid reservoir 30 of the pump. The inlet passageways 26, 26a are spaced approximately 180 degrees apart in the cover member. Each passageway Opens into the surface 24 at radially spaced locations to provide radially inner and outer inlet ports 28a, 28b respectively, for the pumping means 12. The cover member 25 also includes discharge passageways 27, 27a which communicate with the pumping pockets 21 and with an outlet fitting 31 which directs fluid discharged from the pump to the system. The discharge passageways 27, 27:: each open into the surface 24 at radially spaced locations to provide pairs of radially inner and outer discharge ports 29a, 2%, respectively. A pair of ports 29a, 2912 are spaced approximately 180 degrees from the other pair of ports. The cover member 25 additionally includes a central portion which provides a support for a bearing 32 which is operable to rotatably support an end 33 of the shaft 13 therein.

The pumping means 12 is positioned between the cover 25 and an end plate 35. The end plate 35 is fixed in the housing by means of suitable screws 36 which extend through the cam member 15 and are threadedly engaged with the cover 25. The screws 36 maintain the end plate 35 in close proximity to the pumping means 12. The end plate 35 is additionally held in radially aligned relation with the pumping means 12 by means of a locating pin 39 which extends through the end plate 35, the cam member 15, and into the cover 25. The end plate 35, cam 15 and cover 25 provide a unitary assembly which is press fitted into the housing 11 so that the assembly is fixed against rotation relative to the housing.

The end plate 35 includes an axially extending body portion 40 and a radially extending web or flange 41 having a planar surface 42 positioned adjacent the pumping means 12. The body portion 40 supports the shaft 13 by means of a suitable bearing 44 to permit the shaft 13 to rotate relative to the end plate 35. The body portion 40 of the end plate 35 is sealingly engaged with the housing 11 by seal means 46. An inner periphery of the body portion 40 is provided with a fluid seal means 50, shown schematically, located between the body portion and the shaft 13 to prevent leakage of fluid therebetween. The planar surface 42 of the flange portion 41 is provided with pairs of groove portions or chambers 48a, 43b communicated with the inlet of the pumping means 12 by a fluid passage 13a in the shaft 13 and a passage means 48 in the end plate 35. The flange portion 41 also includes pair of groove portions or chambers 49a, 49b communicating with the discharge of the pumping means 12. As shown in the drawings, the grooves or chambers 49a, 4912 are spaced radially apart on the surface 42 and at locations on the end plate corresponding to discharges of the pumping means and are in communication with the discharge passageways 27, 27a in the cover member 25. The inlet grooves or chambers 48a, 48b are in communication with the inlet passageways 26, 26a in the cover member 25 by means which will be described in detail hereinafter and provide a fluid inlet for the pumping means on the axial side thereof opposite from the cover member 25.

The web or flange 41 also includes a port or channel 53 which extends therethrough from each discharge chamber 49a at a discharge of the pumping means 12 and to a fluid chamber 54 defined by the end plate 35 and the housing 11 and located to the left of the flange portion 41, as viewed in the drawings.

Fluid approximately at the discharge pressure of the pump is communicated into the chamber 54 through the port or channel 53 so that the flange 47 of the housing 11 is forced into tight sealing engagement with the body portion 40 and O-ring 46 of the end plate 35 by the fluid pressure in the chamber. Moreover the fluid pressure in the chamber 54 is effective to urge the end plate 35 toward the pumping means 12.

Operation of the pumping means 12 and its associated parts should be apparent from the foregoing. Fluid from the reservoir 30 enters the inlet passages 26, 26a and is directed in part to the pumping means 12 through the inlet ports 28a, 28b in the cover member 25. Fluid in the passageways 26, 26a is also directed through the flow passage 13a in the shaft 13, the passage means 48 in the end plate 35 and to the pumping means 12 through the ports 48a, 48b in the end plate. Inlet fluid entering the pumping means 12 enters the pumping pockets 21 and is pumped through the discharge ports 29a, 29b and 49a, 49b in the cover member and end plate respectively. The fluid flows from discharge ports 29a, 29b and 49a, 49b to the discharge passageways 27, 27a in the cover member 25. Pumped fluid in the discharge passageways is directed therefrom to the system through the fitting 31.

In accordance with the present invention conduit means are provided for controlling fluid pressure acting on the pumping elements 16 during the inlet strokes thereof for increasing the volumetric efl-lciency for the pump and for reducing noise and wear of its parts. The conduit means includes fluid passageways communicating between inlets of the pumping means and which are effective to reduce pressure differentials axially across the pumping elements of the pumping means as well as passageways for directing fluid pressure to the pumping elements.

The groove or chamber portions 48a, 48b in the end plate 35 form radially outer and inner intake 'ports for the pumping means 12. The radially outer groove 48a in the end plate 35 is located adjacent a radially outer portion of the pumping elements 16 and communicates with the inlet passageways 26, 26a in the cover member 25 by means of an opening 64 which extends through the cam member 15 adjacent a point on the cam surface corresponding to the start of the intake stroke of the pumping elements 16. Thus, it will be seen that the fluid pressure at the radially outer inlet port 48a of the end plate is communicated through the cam member 15 and the radially outer intake port 28a to the inlet passageways 26, 26a formed in the cover member 25. The opening in the cam member permits fluid pressure along the axial extent of the roll or pumping elements 16 to be equalized to eliminate tilting of the pumping elements 16 during the inlet stroke which might otherwise occur due to build-up of pressure of fluid trapped in front of the elements.

The radially inner intake port 48!) formed in the end plate 35 is in fluid communication with the inlet passageways 26, 26a in the cover member 25 by means of a flow passage 13a formed in the shaft 13. The flow passage 13a communicates with the intake port 48b through ports 66 extending radially between the passage 13a and the outer periphery of the shaft 13, and a flow passage 67 which forms part of the passage means 48 and communicates with the opening 64. As the shaft 13 rotates the centrifugal forces developed urge fluid from the passageway 13a in the shaft through the ports 66 and into the passage 67, thereby providing a centrifugal boost of inlet fluid pressure. The amount of centrifugal pressure boost is dependent on the diametrical size of the ports 66 and is varied to provide a desired pressure boost by changing the port sizes. The flow passage 67 extends toward and opens into the intake port 4812 so that fluid flowing through the passage 13a in the shaft 13 is directed thereby into the intake port 4812, resulting in the development of fluid pressure forces radially inwardly of the pumping elements 16. These fluid pressure forces urge the pumping elements 16 radially outwardly to maintain the pumping elements in engagement with the cam surface to reduce roll-hop and roll noise. Directing of fluid into the intake port 48b by means of the passage 67 is particularly advantageous at low operating temperatures when the pump fluid has a relatively high viscosity.

Inlet fluid is directed into the passage 13a in the shaft 13 by the operation of a flow controlling means 70 which is associated with the pump and is effective to control the amount of fluid discharged from the pump to the fluid system. The flow controlling means 70 includes a valve member 71 which is slidably disposed in a valve bore 72 formed in the cover member 25. The valve member 71 is movable in the bore 72 between a position wherein fluid discharged from the pumping means into the discharge passageways 27, 27a is directed to the fluid system through the fitting 31, and a position wherein a portion of the discharge fluid is by-passed from the discharge passageways 27, 27a to the inlet passageways 26, 26a. Bypassing of the fluid occurs when the valve member 71 moves to the right as viewed in the drawings.

The flow passage 13a in the shaft 13 opens adjacent the valve member 71 at the left end of the bore 72 so that when the valve member moves to bypass fluid, as described, some of the bypassed fluid is directed into the flow passage 13a and to the inlet port 48b in the end plate 35. When the valve member 71 is in its position where fluid is not being bypassed from the system, fluid in the inlet passageways 26, 26a is drawn through the passage 13a due to the low pressure created at the inlet of the pumping means.

The radially outer inlet port 48a and the passageway 67 are connected by a passageway 68 extending therebetween. The passageway 68 is effective to reduce pressure differentials between the radially outer port 48a and the radially inner port 48b so that pressure differentials acting axially along the pumping elements 16 are reduced accordingly and tilting of the pumping elements during their intake stroke is minimized. Thus, it will be seen that fluid pressure is communicated between the radially inner and outer inlet ports 48a, 48b, by means of the passageways 68, and further that fluid pressure is communicated between the intake ports 28a, 28b in the cover member 25 and the intake *ports 48a, 48b in the end plate 35. The communication thus provided between the intake ports of the pumping means 12 aids in equalizing the pressure of the inlet fluid along the pumping elements as described so that pressure differentials along the pumping elements 16 are substantially reduced, thus reducing the amount of mechanical noise caused by tilting and hopping of the pumping elements 16 at high speeds of rotation or at low temperatures.

It should be apparent that the structure provided increases the volumetric efficiency of the pump due to the resultant increase in fluid taken into the pump on the intake stroke of the member 16. It should further be apparent that a pump embodying the present invention is also effective to reduce pressure differentials axially across the pumping elements of the pumping means resulting in reduction of tilting of the pumping elements and noise created thereby as well as maximizing volumetric efiiciency and life of parts thereof.

While a preferred embodiment of a pump embodying the present invention has been illustrated and described herein in considerable detail, it should be apparent that certain modifications, adaptations and changes of the structure disclosed herein can be made. Therefore the present invention is not to be considered limited to the precise construction shown but rather it is my intention to cover hereby all such modifications, adaptations and changes which come within the scope of the appended claims.

Having described my invention, I claim:

1. A fluid pump for supplying fluid to an external fluid system comprising shaft means, rotary pumping means connected to said shaft means for rotation therewith, said pumping means including a rotor member, a cam member surrounding said rotor member, and pumping roller members carried by said rotor member and movable radially with respect thereto by said cam to effect pumping of said fluid, a first member positioned adjacent an axial side of said pumping means, said first member including an inlet passageway for delivering fluid to said pumping means and inlet port means communicating with said inlet passageway and said pumping means, a second member positioned adjacent an opposite axial side of said pumping means, said second member including inlet port means communicating with said pumping means, and conduit means for communicating fluid from said inlet passageway in said first member to said inlet port means in said second member, said conduit means including a flow passage in said shaft means opening in said inlet passageway and operable to direct fluid therefrom to said inlet port means in said second member and a second flow passage in said second member communicating with said flow passage in said shaft means and with said inlet port means in said second member, said second flow passage operable in direct inlet fluid from said flow passage in said shaft means into said pumping means radially inwardly of said pumping roller members to urge said roller members toward said cam member.

2. A pump as defined in claim 1 and further including flow control means for metering the flow of discharge fluid from said pumping means to said system and including a valve member movable from a first position wherein fluid in said discharge passageway is directed to said system to a position wherein part of said fluid in said discharge passageway is by-passed to said inlet passageway, said valve member effective in its by-pass position to direct by-pass fluid into said flow passage in said shaft means.

3. A fluid pump for supplying fluid to an external fluid system and comprising shaft means, pumping means drivingly associated with said shaft means, said pumping means including a pumping rotor connected to said shaft for rotation therewith, a cam member surrounding said rotor and fixed against rotation, and pumping elements carried by said rotor and movable radially relative thereto by said cam member to effect pumping of said fluid, first and second members positioned at opposite axial sides of said rotor and providing axially spaced inlet port means for said pumping means, and conduit means communicating with one of said port means for directing inlet fluid to said pumping means radially inwardly of said pumping elements to urge said pumping elements radially outwardly of said rotor during an intake pumping stroke thereof, said conduit means including a first fluid passageway formed by said shaft means and extending to a second fluid passageway in one of said members, said second fluid passageway extending from said first passageway to said port means in said one member at a location radially inwardly of said pumping elements.

4. A fluid pump as defined in claim 3 wherein said inlet port means in said one member include radially inner and outer chambers positioned adjacent said pumping means and opening thereinto, with said radially inner chamber located radially inwardly of said pumping elements during an intake stroke thereof, and wherein said second flow passage opens into said radially inner chamber to direct fluid into said pumping means radially inwardly of sad pumping elements.

5. A fluid pump for supplying fluid to an external fluid system comprising shaft means, pumping means including a pumping rotor connected to said shaft means for rotation therewith, a cam member having a cam surface surrounding said pumping rotor, and pumping roller members carried by said rotor member and movable radially relative to said rotor by said cam surface of said cam member to effect pumping of said fluid, first and second members positioned on opposite axial sides of said pumping means and providing axially spaced inlet ports for said pumping means, said inlet ports communicating with said pumping means adjacent a radially outer portion of said pumping roller members, conduit means communicating with said axially spaced inlet ports for substantially equalizing radially inwardly directed fluid pressure forces acting axially along said roller members to thereby reduce noise created by said pumping means, and a second radially inner inlet port opening into said pumping means radially inwardly of said roller members, one of said members including a fluid passageway communicating with said inlet ports thereof.

6. A pump as defined in claim 5 wherein said conduit means includes an axial opening in said cam member extending between said axially spaced inlet ports.

7. A fluid pump for supplying fluid to an external fluid system comprising shaft means, pumping means including a pumping rotor connected to said shaft means for rotation therewith, a cam member having a cam surface surrounding said pumping rotor, and pumping roller members carried by said rotor member and movable radially relative to said rotor by said cam surface of said cam member to eflect pumping of said fluid, first and second members positioned on opposite axial sides of said pumping means and providing axially spaced inlet ports for said pumping means, said inlet ports communicating with said pumping means adjacent a radially outer portion of said pumping roller members, conduit means communicating said axially spaced inlet ports for substantially equalizing radially inwardly directed fluid pressure forces acting axially along said roller members to thereby reduce noise created by said pumping means, a second radially inner inlet port in one of said members and a flow passageway in said one member, said flow passageway in said one member operable to direct a flow of inlet fiuid into said pumping means through said second inlet port to provide radially outwardly directed fluid pressure forces acting on said roller members to urge said roller members into engagement with said cam member.

References Cited UNITED STATES PATENTS 2,725,013 11/1955 Vlaohos 103-136 2,808,004 10/1957 Durant et al. 103-136 2,818,813 1/1958 Pettibone 103-136 2,823,614 2/1958 Lapsley 103-136 3,204,566 9/1965 Feroy 103-136 3,207,077 9/ 1965 Zeigler et a1 103-42 3,273,503 9/1966 Clark et a1 103-136 X 3,329,067 7/1967 Rosaen 103-136 FRED C. MATTERN, In, Primary Examiner. o W. J. KRAUSS, Assistant Examiner. 

